Oxygen admission valve for oxygen re-breathing apparatus



`Fel. 12, 1957 c. J. LAMBERTSEN 2,781,043

OXYGEN ADMISSION VALVE FOR OXYGEN vRl-BRET'ING APPARATUSv Filed DEC. 21, 1.*955

BTTORNBYS OXYGEN ADMISSION VALVE FOR OXYGEN IRE-BREATHING APPARATUS 8 Claims. (Cl. 12S-142) This invention relates to breathing apparatus of the type adapted for use under water, in atmospheres where toxic or poisonous gases may exist, or where a normal amount of oxygen in the air is insuicient.

in my prior patent No. 2,456,130, I have disclosed a breathing apparatus of the closed-circuit, re-breathing type, that is, a breathing apparatus having a rta-breathing bag from which the wearer inhales and into which the exhaled gases pass, after separation therefrom of the exhaled carbon dioxide. Such apparatus also includes a source of oxygen which is supplied to the re-breat-hing bag in regulatable amounts.

The present invention is concerned with means for automatically admitting oxygen, or an oxygen-containing gas from a source of supply to the re-breathing bag of a breathing apparatus, of which the breathing apparatus or my foresaid patent is representative.

More particularly, the present invention contemplates a novel means for automatically opening the valve which controls the flow of oxygen from the oxygen source to the 1re-breathing bag in accordance with the pressure diierential between the inside of the re-breathing bag and the exterior pressure exerted thereon. Thus, as oxygen is consumed by inhalation of the user, the pressure within the re-breathing bag will be reduced, and the greater pressure exerted on the outside of the bag will cause the valve to be opened to permit ow of oxygen into the rebreathing bag from a source of supply thereof until the pressure within the re-breathing bag again is equal to the external pressure exerted on the exterior thereof. Thus, oxygen will be admitted to the re-breathing bag with each inhalation in substantially the exact volume required to meet the needs of metabolism of the user of the apparatus under all conditions.

The valve which controls the ilow of oxygen, while being actuated by the pressure exerted on the exterior of the re-breathing bag, is located within the re-breathing bag and is actuated through a exible diaphragm forming a part of the wall Aof the re-breathing bag. Such ilexible diaphragm is suitably protected against engagement by extraneous objects or the like which might cause an operation of the admission valve independent of the pressure exerted on the outer face of the flexible diaphragm.

The invention will be further described in connection with the accompanying drawings which illustrate a preferred form of the invention.

ln the drawings:

Fig. l is a sectional View through a re-breathing bag embodying the automatic oxygen-admission valve of the invention;

Fig. 2 isa plan view of the automatic valve unit taken on line 2 2 of Fig. l; and

Fig. 3 is a sectional view through the re-breathiug bag taken on a line corresponding to line 3-3 of Fig. l.

Referring now to the drawings, reference character 1 designates a re-breathing bag of a closed-circuit, rebreathing apparatus which preferably is formed of rubberized fabric or of some other exible, non-distensible material, and which corresponds to the re-breathing bag of my foresaid patent, to which reference is made for a fuller disclosure of the nature of the re-breathing bag and the closed-circuit type of breathing apparatus with which it may be used. For the purpose of the present disclosure, it is suici-ent to point out that the re-breathing bag contains oxygen which the wearer inhales through a mask and proper valve connections, and into which the wearers exhalations pass after the exhaled carbon dioxide has been absorbed therefrom; and that the re-breathing bag is connected to a source of oxygen or oxygen-containing gas, which preferably is carried by the wearer as part of the re-breathing apparatus.

The automatic oxygen admission valve is located within a casing or housing 2. This casing is elongated and suiiiicently small in transverse cross-section that it may be inserted into and removed from the breathing bag through one of the breathing tube openings. Hence, although sealed in the breathing bag, it may be removed for servicing at any time should occasion demand. The casing 2 is provided with a bearing surface 3 at one side thereof from which an inlet nipple 4 extends. The nipple extends through an opening in the adjacent side of the re-breathing bag, and the casing is secured to the rebreathing bag by means of a nut 5 and packing washer 6. When the nut is threaded tightly against the packing washer the re-breathing bag adjacent the nipple is clamped between it and the bearing surface 3 and a watertight connection between the re-breathing bag and the valve casing is obtained.

The outer end of the nipple 4 protrudes beyond the nut 5 a distance suicient to make a threaded connection with a tube 7 extending from a source of oxygen or an oxygen-containing gas.

The wall of the casing 2 next to the adjacent side or" the re-breathing bag is formed with a gas passage 8 which connects the space within the nipple 4 to a space 9 at one end of the housing.

The automatic oxygen-admission valve is removably mounted in the casing 2 adjacent the space 9. It consists of a valve seat 10 having openings 11 for the passage of oxygen and a valve head 12. The valve seat is securely held against a shoulder 13 formed on the inside of the casing by a bushing 14 having a threaded engagement with the casing behind the valve seat. When the bushing 14 is threaded tightly against the peripheral edge portion of the valve seat, an elective seal is made which prevents leakage of oxygen around the edge of the valve seat. The valve seat has an annular tl-shaped ridge 15 for engagement with the valve head. The valve head is recessed at the side adjacent the valve seat to receive a rubber or other resilient pad 16 which engages the rl-shaped ridge of the valve seat to make an eitective seal therewith.

A valve stem 17 extends from the valve head 12 through the valve seat and a substantial distance inwardly or the casing 2. The opening in the valve seat through which the valve stem extends is substantially larger than the valve stern to permit lateral movement of the valve stem sufficient to force one Side of the valve head away from the V-shaped ridge of the valve seat, as will hereinafter be more fully described.

A conical coil spring 18 has its smaller end secured to the valve stem 17, as at 19, while its other end bears against the valve seat. The spring 1S is under compression and thus exerts a force on the valve head, through the valve stem, which normally holds the valve head against the valve seat, thereby preventing oxygen from owing past the valve into the rev-breathing bag. The conical spring 18 also tends to centralize the valve head with respect to the valve seat.

A lever 20 has one end thereof pivotally mounted on a pintle 2l removably mounted at the end of the casing remote from the end having the valve mechanism therein. The lever extends forwardly in the casing a distance suicient to overlie the Vfree end of the valveY stern 17. The free end of the lever has an extension 22 at right angles thereto; and the free end of the extension is notched or bifurcated to provide arms 23 which straddle the valve stem and prevent it from being displaced relative to the lever.

' The end of the casing remote from the valve mechanism Y is left open to permit ready assembly and removalrof the valve and its associated parts. The casing also is provided with an opening 24 of substantial size at the side opposite that at which the nipple ftextends and at a position opposite the free end of the lever 2i?.

The side of the re-breathing bagV opposite that to `tvhich the casing 2 is attached is cut away, as at 25, and the opening thus made is sealed oya exible membrane or diaphragm 26 having an actuating bar or member 27 secured to the inner side thereof opposite the free end 0f the lever 20. As shown in Fig. 3, the bar 27 extends a substantial distance at each side of the valve stem 17 and the lever 2u,

An outwardly-convex disc 28 of a non-flexible material is mounted over the cut-away portion of the breathing bag at the outer side thereof. The disc 28 has openings 29 therein through which the pressure of the surrounding media may act on the flexible diaphragm v25. The disc 23 prevents theV diaphragm'from being constantly forced inwardly by external physical engagement, yet, through its openings 2.9, permits the pressure of the surroundingV media to be eiiective against the outside of the diaphragm.

The construction of the valve casing 2 is such that it protects the valve from activation byexternal forces on three sides. The outwardly-convex rigid disc 2S, on inhalation, is forced inwardly by the then greater pressure of the surrounding fluid media and its peripheral portions come to rest on the ends of casing 2, beyond the ends of the opening 24 therein. Hence, this rigid disc completes the protection Yof the Vvalve from external activation and assures that the operation of the valve will depend soleiyV on the pressure differential between the oxygen within the breathing bag and the surrounding media.

The securing of the casing 2 to the breathing bag at a point directly opposite the actuating bar'27, and the extension of the valve actuating lever 2t) so that its free end portion is in alignment with the actuating bar 27 and the axis of the connecting means assure actuation of the valve at all times when the external pressure exceeds that of the internal pressure by an amount sui'icient to forceY the actuating bar 27 inwardly a distance far enough to cause it to engage the lever 20. This is true even though .shifted laterally with respect to the inner side of the arm.

The function of the admission valve is essentially to :supply toa breathing bag of limited volume, a functionally-unlimited volume of oxygen on inhalation.

Hence, though the valve is actuated by changes' in pres-V sure, it is a volume demand val'e. Y Even though the breathing bag is limited in size, the operation of the valve is such that the breathing bag cannot be emptied by a single inhalation. V i

With the parts as described, the pressure of the surrounding media is effective through the openings 29 of the disc 2S against the outside of the diaphragm 26, and, when the pressure within the refbreathing bag is less than the pressure of the surrounding media, the ilexible diaphragm 26 will be forced inwardly of the re-breathing bag, thereby causing the bar 27 to engage the free end of the lever 26 and move it in the directionrof the valve stem. This causes the bifurcated end of the lever' extension 22 to engage the valve stem and move it laterally. Y

This latter movement causesl one side of the valve head 2, to be dislodged or moved away from the valve seat l@ to provide a space for the passage of oxygen past the valve. This condition will exist as long as, and at any time when the pressure within the breathing bag is less than of the surrounding media. At all otherV times the valve effectively prevents flow of oxygen fromthe oxygen container into the re-breathing bag.

When a ire-breathing apparatus embodying the automatic oxygen-admission valve of the invention isV in use,

- and the wearer inhales, a certain amount of the oxygen Y within there-breathing bag will be removed and the pressure within the re-breathing bag will be reduced accordingly. This disturbance of the pressure equilibrium within and without the re-breathing bag will result in the now greater pressure on the outside of the re-breathing bag being Vedective to move the iexible diaphragm 26 inwardly until the bar`27 engages the free end of the lever Etf, and through it moves the valve stern 17 laterally to slightiy open the'valve 'i2 and permit oxygen to flow therepast into there-breathing bag until the pressure equilibrium again has been re-established. Thus, oxygen automatically` will be admitted by the normal inhalation of the user of tie apparatus with each breath inthe exact volume required to meet the needs of his metabolism at all times.

Since the oxygen is admitted into the re-breathing bag Vof mean Water pressure exerted upon the outside of the users chest. Thiscauses the .valve to function when'the pressure within'the re-breathing bag and, hence, within the lungs, is equal to the average mean Water pressure acting upon the outsideY of the chest Wall. By so locating the valve triggering mechanism,'undue changes in intralung pressures which Would disturb circulation ofV the blood through the heart, lungs and brain are prevented.

While the invention has been described in connection with a preferred embodiment theerof, it is to be under-V stood that various changes may be made in the details of construction without departing from the scope of the invention or sacrificing any of the `advantages thereof, the scope of the invention being defined in the appended claims. Y Y

I claim: J i Y l. In a breathing apparatus, re-breathingbag, a valve within theV re-breathing bag, said valve having a valve seat and a valve head, means for connecting one side of said valve to a source of an oxygen-containing gasthe other side of said valve'being in communication with the interior of theire-breathingfbag, a valve stem extending from the valve head, Va flexible diaphragm forn1- ing a part of the wall of the re-breathing bag, mechanism operable upon an inward distension of the ilexible diaphragm due to a greater Y external pressure thereon to engage and move the valve stem in aidirection to dislodge the valve head from the valve seat andV thereby permit oxygen-containing gas to flow past the valve into the breathing apparatus, and a uid-pervious member extending over the outsideof the flexible diaphragm to prolect it against inward distension except when the pressure of the surrounding media is greater than the pressure within the re-breathing bag.

2. In a breathing apparatus, a rebreathing bag, a valve within the re-breathing bag, said valve having a valve seat and a valve head, means for connecting one side of said Valve to a source of an oxygen-containing gas, the other side of said valve being in communication with the interior of the re-breathing bag, a valve stem extending from the valve head, a llexible diaphragm forming a part of the Wall of the re-breathing bag, 'and a lever mounted to engage and move the valve stem to dislodge the valve head from the valve seat upon an inward -distension of the flexible diaphragm due to a greater external pressure thereon and thereby permit oxygen-containing gas to flow past the valve into the breathing apparatus, the portion of the lever which engages the valve stern being bifurcated and having the resultant arms straddling the valve stem to prevent displacement of the Valve stem relative to the lever.

3. In a breathing apparatus, a re-breathing bag, a valve within the re-breathing bag, said valve having a valve seat and a valve head, means for connecting one side of said valve to a source of an oxygen-containing gas, the other side of said valve being in communication with the interior of the re-breathing bag, a valve stem extending from the valve head, a exible diaphragm forming a part of the wall of the re-breathing bag, an actuating member mounted on the inside of the flexible diaphragm, a lever mounted to be engaged by said actuating member and operated to move the valve stem to dislodge the valve head from the valve seat upon an inward distension of the lexible diaphragm due to a greater external pressure thereon and thereby permit oxygen-containing gas to ilow past the valve into the breathing apparatus.

4. In a breathing apparatus, a re-breathing bag, a valve within the re-breathing bag, said valve having a valve seat and a valve head, means for connecting one side of said valve to a source of an oxygen-containing gas, the other side of said valve being in communication with the interior of the re-breathing bag, a valve stem extending from the valve head, a exible diaphragm forming a part of the wall of the re-breathing bag, a lever mounted to engage `and move the valve stem to dislodge the valve head from the valve seat upon an inward distension of the flexible diaphragm due to a greater external pressure thereon and thereby permit oxygen-containing gas to ow past the valve into the breathing apparatus, and a casing enclosing said valve stem and said lever, said casing being open at one side to permit actuation of the lever and valve stem when the exible diaphragm is distended inwardly.

5. In a re-breathing apparatus as set forth in claim 4, the further improvement in which the lever is pivotally mounted in the casing at the end thereof remote from the valve mechanism and the free end of the lever straddles the valve stem.

6. In a re-breathing apparatus as set forth in claim 4, the further improvement in which the casing is secured to one side of the re-breathing bag, the opening in the casing is at the side thereof remote from the side attached to the re-breathing bag and the exible diaphragm is at the side of the re-breathing bag opposite to that to which the casing is attached and opposite the opening in the casing.

7. A valve unit for use in a re-breathing apparatus comprising a casing, a valve seat within said casing, a valve head for engaging said valve seat, means connecting one side of said valve to a source of an oxygen-containing gas, an outlet from said casing, the other side of said valve being in communication with said outlet, a valve stem extending from said valve head, and a lever pivoted to said casing and having its free end engaging the valve stem for movement thereof laterally to dislodge the valve head from the valve seat, the casing having an opening opposite the rree end of the lever for the passage of a member to engage the lever and cause it to move the valve stem.

8. In a breathing apparatus, a `re-breathing bag, a valve unit within the re-breathing bag, means mounting the valve unit on one side of the re-breathing bag, said valve unit including a casing having a passage therethrough for an oxygen-containing gas and an opening at the side thereof opposite to the side which is attached to the rebreathing bag, a valve in said passage for controlling the ilow of the gas therethrough, said valve having a Valve head and a valve seat, a valve stem extending from the Valve head, a exible diaphragm forming a part of the Wall of the re-breathing bag opposite the opening in said casing, a lever mounted to be moved to a position to engage the valve stem and to move it in a direction to cause the valve head to at least in part be moved from the valve seat, means carried by said tlexible diaphragm for engaging and actuating said lever upon inward distension of the flexible diaphragm, said mounting means for the valve unit, a portion of said lever, the opening in the casing and the actuating means for the lever being in alignment, whereby the existence of a pressure on the outer side of the flexible diaphragm greater than the pressure on the inner side thereof will cause an inward distension of the diphragm and an opening of the valve irrespective of the relative position of the valve unit to the portion of the re-breathing bag on which it is mounted.

References Cited in the le of this patent UNITED STATES PATENTS 1,225,269 Paul et al. May 8, 1917 2,452,670 Meidenbauer Nov. 2, 1948 2,456,130 Lambertsen Dec. 14, 1948 FOREIGN PATENTS 212,167 Great Britain Mar. 6, 1924 

